Multiple fuse



June 10, 1924. 1,496,907

J. SCHURY MULTIPLE FUSE Filed April 15 I922 il limi WEE-Jil f Quvcntm FE. q.5 U do why Chimney? Patented June 10, 1924.

UNITED STATES JOEN SOHUBY, OF DBTBDII, 110816.

I'ULTIPLB iusx.

Application aim A ril 15, 1922. Serial ll'o. 553,150.

To all whom it may concern: Be it known that I, JOHN SCHURY, a citizen of Austria, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and. useful Imrovements in Multi le Fuses, of which the ollowing is a s cification, reference being had therein to t e accompanying drawings. This invention relates to fuses and has special reference to multiple fuses wherein rotary plugs are provided with a plurality of fuses that may be successively s ifted to active positions, thus permitting of a ood fuse being substituted for a blown-out use, and such fuses obviate the necessity of using individual fuses when electric circuits are to be completed.

My invention aims to provide a multiple fuse which is sealed and cannot be conveniently tampered with after the parts of the fuse are assembled, thus providing a fuse which meets with the requirements of the Underwriters Association pertaining to such matters.

My invention further aims to furnish a fuse of the above class with a spring pressed contact member of a configuration which will not interfere with rotations of a multiple fuse plug and which will at all times insure a ositive contact with one of the fuses of e plug.

My invention further aims to accomplish the above results by a durable and inexpensive construction that will be hereinafter described and then claimed and reference will now be had to the drawing, wherein-- Fi re 1 is a view of one side of a multiple se in accordance with my invention;

Fig. 2 is a view of the opposite side of the fuse;

Fig. 3 is a longitudinal sectional view of the fuse;

Fig. 4 is a horizontal sectional view taken on the line 4-4 of Fig. 3;

Fig. 5 is a side elevation of the rotatable plu provided with a multiple fuse;

li lg. 6 is a view of the inner end of the same;

Fig. 7 is a perspective view of the multiple fuse per se;

Fig. 8 1s a plan of a blank mult1 le fuse,

Fi 9 is a view of the outer en of the comp ete fuse'as shown in Figs. 1 to 3 inclusive, and

Fig. 10 is a horizontal sectional view taken onthe line 9--9 of Fig. 3.

In the drawing, the reference numeral 1 denotes a cylindrical body made of a suitable insulation material, and said body is exteriorly screwthreaded, as at 2, to receive a screw cap 3 having a central opening 4. The cap 3, about the opening 4, is provided with indicia 5 relative to the number of fuses within the fuse body.

The bogs 1 has an exteriorly screwthreaded reduc end 6 on which ismounted a sleeve 7, said sleeve being also screwthreaded so that the reduced end of the fuse body may be screwed into a socket in the usual manner. The reduced end 6 of the fuse body terminates in'a nose 8, and said fuse bod has a lar e cylindrical chamber 9 exten mg from t e inner end of the body 1 into the reduced end 6 thereof and said chamber, within the reduced end 6, has longitudinal equally spaced ribs 10 on a semi-cylindrica portion of its wall cooperating with the remaining portion of the wall in forming end abutments 11.

In the chamber 9, at the nose end of the body 1 is a central frustro conical shaped boss 12 and axially of said boss is a ternnnal 13 having an inner contact member 14 and an outer contact member 15. The outer contact member 15 is adapted to establish electrical connection when the fuse body is screwed into a socket.

The chamber 9, at the inner end of the body 1 has a wall recess 37 communicating with an opening 16 in said body at the reduced end 6 thereof, and the shell 7 extends to the mouth of said opening, so that said shell may be soldered or otherwise connected, as at 17 to a sprin pressed contact member 18 set in the wall recess 37. With one end of the contact member 18 soldered to the shell 6 the opposite end of said contact member may be sprung and it is this end of the contact member that is engaged by a coiled expansion spring 19 set in the recess 37. The ex ansive force of the spring 19 forces the en of the contact member outwardly from the recess 37 and said contact member has a bent or cam edge 20 by which the contact member may be forcibly caused to recede into the recess 37, when switching from one fuse to another as will hereinafter ap ear. The end of the contact member 18 is ent outwardly to form alin 21 so as not to interfere with the insertion'of a plug in the body 1, and the manner in which the contact member is mounted prevents said contact member or the spring 19 from becoming accidentally displaced.

The reference numeral 22 denotes an invertedfrustro conical shaped plug provided with a head 23, a peripheral flange 24 and a tang or finger piece 25. The plu is made of a suitable insulation materia and is placed in the chamber 9 with the flange 24 enga ing the cap 3 and the head 23 extending through the opening 4 of the cap, so that the tang or finger piece 25 will be exposed for rotating the lug. On the head 23 or the tang 25 may e placed indicia relative to direction of rotation of said plug, also the number of amperes for which fuses are intended.

The plug22 has an inner reduced end 26 provided with a concave recess 27, and the outer walls of said plug are provided with longitudinal grooves 28 communicating with notches29 in the lower face of the flange 24. The recess 27 has its walls notched,-as at 30 with the notches opening into the grooves 28, and the plug 22' has an annular shoulder 31 which w1ll en age the abutments 11 and limit the inwar movement of the plug should such limitation be necessary.

The reference numeral 32 denotes a mul tiple fuse blank or spider having a plurality of radially disposed fuses 33 provided with neck portions 34 connecting the fuses to the spider'or blank 32, and these multiple fuses are adapted to be cut and stamped from sheet'metal of such gauges as will afford fuses of various thicknesses. The metal used for the fuses is of a fusible nature of predetermined conductivity and the thickness or strength of each fuse will determine the amperes that may be safely carried thereby, any overload causing the fuse to burn or blow out.

The fuse spider or blank 32 is shaped to fit in the recess 27 with the neck portions 34 engaging in the notches 30 and the fuses 33 extending along grooves 28 into the notches 29. In practice, the fuse blanks are bent' and mounted on or in the plugs by a special machine designed for such purpose, and with the fuse blank or spider 32 providing an inner lining for the recess 27, said fuse blank or spider will contact with the contact member 14 of the terminal 13. The boss 12 has a configuration cooperating with the contact member 14 in permitting the lug to be fitted down over the contact member 14 and rotated thereon. The plugis adapted to be turned in a clockwise direction so that the ribs formed by the grooves 28 will impinge against the cam ed e 20 of the contact member 18 and cause said member to recede until it may rebound into one of the grooves 28 and en age the fuse 33 therein. By reference to ig. 4, it will benoted that the grooves 28 are of sufiicient when the plug 22 is rotated in a clockwise direction there is a snapaction as the contact member .18 enters the groove. This snap action will permit of the operator of the fuse plug determining when the plug has the multiple fuse, without discarding the body or plug thereof. In some instances such renewal, particularly by the user, is' prohibitive so in order to prevent such practice I may seal or fix the cap 3 to prevent its removal and access to the plug 22. This is accomplished by providing the body 1 with one or more notches 35 and depressing or indenting the cap 3, as at 36 until said cap enters the notch and cannot be rotated. The indenting of the cap may be easily accomplished by a special die and after the cap is so locked on the body it cannot be conveniently removed, and consequently the user of the fuse cannot reload the fuse body with fuses that may be of greater strength than actually intended for a safe electric circuit.

-I attach considerable importance to the construction of the contact member, also the ribs on the inner walls of the insulator body,"

as these ribs reduce the frictional contact 1 between the plug and the body so that with the plug bearing on the terminal of the body there is no danger of the walls of the plu binding against the walls of the bod an -interfering with rotation of the plu 1n the the structural elements are susceptible to' such variations and modifications as fall within the scope of the appended claims.

What I claim is 1. In a multiple fuse wherein a rotary plug is mounted in a body adapted to be mounted in a socket, and fuses carried by said plug are adapted to be brought successively into electrical connection with the socket ;means for establishing such connection, said means comprising a contact width to receive the contact member 18 and member in said body adapted to be engaged by the fuses of said plug, said contact member. having an end lip to facilitate mounting said plug in said body and a cam edge to facilitate rotation of said plug in said body,

and an expansion spring between said body and contact member to msure a positive engagement between said contact member and said plug fuses.

2. In a multiple fuse wherein a rotary fuse carrying plug is mounted in a body and adapted to be rotated therein, to establish an electrical connection ;means supporting said plug for easy rotation in said body,

said means comprising a terminal in said body, and ribs on the inner walls of said body reducing the frictional contact between said body and said plug.

3. A multiple fuse as in claim 2, wherein the ribs on said body afi'ord end abutments to limit inward movement of said plug.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN SCHU'RY. Witnesses G. E. MCGRANN, KARL H. BUTLER. 

